Motor controller



Aug. 14, 1928. 1580;495-

1'. E. BARNUM ET AL I MOTOR CONTROLLER Filed Oct. 18. 1920 ATTORNEYINVENTOR I Thyme. E. Ban/mum.

" UNITED STAT ES PATENT ,1,680,4es FFICE.

worms 1:. BARNUM, or wau'warosa, Ann-nanny 1w. wens, 'orsnoanwoon,w'rsconsm, assrenons 1'0 TEE CUTLER-HAMMER, use. 00., or MILWAUKEE,WISOON- SIN, A CORPORATION 01 WISCONSIN.

moron conraonnan.

i Application filed October 18, 1920. Serial 1T0; 417,698.

This invention relates to motor controllers and is particularlyapplicable to auto transformer starters for A. C. motors althoughcertain features thereof are applicable to 5 various forms ofcontrollers for both A. C. and D. C. motors.

In practice it is frequently desired to 1nclude in the circuit of thecontrolled motor a transformer or other starting means for a I cafiycompleting running connections, and the present inventions has among itsobjects to provide a controller with simple and efficient means to sofunction. I Another object is -to provide a starter wherein the timeelement is afforded by electro-thermally controlled means whic may beconnected-in circuit to permit immediate restarting after stopping oralternatively connected in circult to delay restarting for a given time.

Another object is to provide a transformer .starter minimizing thenumber of points at which the power circuit must be made and broken.

Other objects and advantages will hereinafter appear.

In the. accompanying drawing, wherein are illustrated certain of theembodiments which the invention may amume in practice, 4

r view illustrating the complete controller;

while v Fi 2, 3 and 4 are similar views-illustrating'si ht modificationsof portions of the control er shown in Fig. 1.

In the drawing'is shown a three phase alternating current gmotor M, asupply circuit L L and L therefor, auto transformer coils 1 and 2 to beconnected in circuit for, starting, and electro-responsiveswitches in-"iven period of time, thereafter automati- Fig. 1 is a schematic anddiagrammatic former coils and to connect the motor to reduced voltagetaps of said coils. Closure of the line switch during gization of thecommutatlng switchserves to connect the transformer coils and the motorin the aforedescribed relation to the supply circuit, whereas,subsequent deenerglzation of the 'commutating switch and consequentreturn movement to the position illustrated serve to interrupt theinterconnection between the transformer coils and to continued ener- Iestablish-connections for the motor through the running switch directlyto the supply circuit. An electrothermally responsive de-' vice 7 servesto time the a-foredescribed der-energization and return movement of thecommutating switch.

More articularlyv said timing device is preferabl of the type disclosedand claimed in a copending application of Erwin R. Stoekle, S. N.358,601, filed Feb. 14, 1920, and comprises in its essential aspects aninsulating container having electrodes penetrating therewithin andnormally electrically connected by a quantity of mercury. Said containeris provided with a reduced portion located between the aforementionedelectrodes and normally containing a portion of the mercury, connectiontherebetween j said reduced portion of the container being furthersurrounded by or otherwise associated with'an el ctrical heating element8 the arrangement being such that upon pre-' determined energization ofsuch element for a given time the mercury within said restricted portionof the container becomes vice is arranged to controlcontinuity of the I-energizing c rcuit of the actuating coil of commutati'ng' vswitch 4.The heating element 8 is arranged to be supplied with elec-' vaporizedwithconsequent sudden interrupwhereby circuit trical energy, preferabl'by means of an" auxiliary coil .9'arra in inductive relation to one ofthe. coils as illustrated, whereby assumm con-;

'stant voltage of the supply circuit, t e deprincipal transformer vicemay becalibrated to provide for deenergization of the commutatingswitcli following a given time element corresponding to the necessaryordesired motor acceleration period.

Said switches 3 and 4 are further provided with auxiliary contactsadapted to provide electrical interlocks to prevent operation of saidswitches exce t in the desired sequence. The switch 3 1s thus providedwith auxiliary contacts 10 arranged to close when said switch is openand vice versa, and with a further set 11 of contacts to be closed whensaidvswitch is closed and vice versa. Similarly the switch 4 is providedwith sets 12 and 13 of auxiliary contacts adapted to be closed onlyduring energization of the actuating coil of said switch.

It is further obvious that either or both of switches 3 and 4 may bemanually actuated, the windings of such switch or switches thenperforming only holding and releasing functions, the various interlocksand the timing device moreover performing their normal functions formaintaining the proper operative sequence subject to a suitable timeelement. J

The operation of the controller and the various circuits involved may bedescribed as follows: Upon closure of the starting button 5 circuit isestablished from line L through stop button 6 thence by conductors 14and 15 through auxiliary contacts 10 of the line switch 3, thence byconductor 16 through said starting button by conductor 17 through thecoil of the commutating switch 4, by conductor .18 through the tim ingdevice 7 hence by conductors 19 and 20 to line L The switch 4 thereuponresponds and moves its several contacts from the position illustrated tothe opposite position for effecting the connections aforedes'cribed.

Such action of the switch 4, also serves by means of its auxiliarycontacts 12 toparallel both the starting push button 5 and the auxiliarycontacts 10 of the switch 3, whereby the energizing circuit of saidswitch 4 is maintained irrespective of opening of said starting buttonand of subsequent closure of the switch 3. Also the aforementionedaction of the switch 4 serves to complete the energizing circuit of theswitch 3, said circuit extending from line L through the stop button 6as formerly traced thence by conductor 14 through the energizing coil 0the switch 3 by conductors 21 and 22 through auxiliary contacts 13 ofswitch 4 which is now closed, thence by conductor 20 to line L3. Theline switch 3 thereupon closes completing the starting connections forthe motor.

Said connections while obvious may be briefly described" as follows. Thetransformer circuit maybe traced from line L through the left handcontacts of switch 3,

thence by conductor 23 to and through coil 1, by conductor 24 throughthe left hand intermediate contacts of switch 4 by conductors 25 and 26through the intermediate con: tacts of switch 3 to line L similarly fromline L through the right hand contacts of switch 3 by conductor 27through coil 2, by conductor 28 through the right hand intermediatecontacts of switch 4 and by conductors 29 and 26 to line L as formerlytraced. The motor circuit extends from the intermediate tap oftransformer coil 1 by conductoi's 30 and 31 through the motor to.conductor 26 thence to line L as formerly traced, also from theintermediate tap of transformer coil 2 by conductors 32 and 33 throughthe motor to conductor 26 and thence to line L Also closure of theswitch 3 serves by means of its auxiliary contacts 11to parallel theauxiliary contacts '13 of the switch 4 whereby the energizing circuit ofsaid switch 3 is maintained irrespective of subsequent retiirn movementof the switch 4.

It is furthermore apparent that upon en ergization of the transformerwindings du to the aforementioned closure of switch 3 thl coil 9 isenergized for supplying current t the heating element 8 of the timingdevici 7 and following a predetermined time inter val said device isadapted to respond in th manner aforedescribed for interruption o theenergizing circuit of the switch 4. Sai switch is thereupon adapted toreturn auto matically to the position illustrated thereb interruptingthe interconnections of th transformer coils and the connections 0 saidcoils to line L and also serving t shunt said coils through conductors34 an 35 for establishing connections for th motor through the lineswitch 3 directly t the supply circuit.

Such return movement of switch 4 als serves through opening of itsauxiliary coi tacts 12 to provide against re-establishmci of theenergizing circuit of said switch fo lowing subsequent automaticresetting of tl timing device 7. I Also under the foregoin conditions itis to be noted that closure switch 3 serves through opening of its an:iliary contacts 10 to provide against re-ene gization of the switch 4following accident or unauthorized actuation of,the start bu ton afterconductiv ty of the timing devil f 7 has been reestablished.

Stopping of the motor is effected by ope: ing the stop button 6 therebyde-energizir the circuit of the switch 3 which thereupi opens anddisconnects the motor and tran former from the supply circuit.

In addition to its aforedescribed fun tions the timing device 7 beingthus 1 sponsive to the electrical condition of t transformer isadapted'to afford protecti to the same by preventing unduly prolongenergization thereof. Also from the fol starting of the motor is notdesired, it is possible to connect the heating element 8 directly acrossone phase of the motor circuit as illustrated in Fig. 2. Under suchconditions the timing device is rendered responsive immediately uponestablishment of startlng connections and 1s moreover calibrated tocause establishment of running connections subject to a suitable timeelement. The element 8 being continuously energized duringenergization'of the motor, the device is prevented from resetting duringrunning and until a given time after stopping of the motor, restartingbeing con- I sequently delayed during such period.

Should it be desired to thus provide against immediate restarting andalso to provide the aforedescribed protection of the transformer, it ispossible to employ two timing devices arranged in series in theenergizing circuit of the switch 4, the individual heating elementsof-said devices being connected ,as illustrated in Fig. 3 of thedrawing. Also a similar result may be obtained by providing a singletiming device as shown in Fig. 4, said device having one heating elementconnected-as illustrated in Fig. 1 and also provided with an auxiliaryheating element connected as in Fig.2, such latter element being sodesigned as to be substantially inac-' 'tive during the starting period,its function being to prevent cooling of the device sufficiently topermitt 'resetting thereof until a given time after s opping of themotor;

ing operation and retention to establish and maintain startingconnections, and further including an electro-magnet to retain saidelement in starting position, of means for timing establishment ofrunning connections by said former means, said latter means including anormally closed electro-thermal relay responsive subject to a timeelement .upon establishment of starting connections.-

3. In a motor controller the combination with means operable toestablish starting connections, said means including electromagneticallyrestrained means releasableto establish running connections, of circuitcontrolling means including a fluid through which the energized circuit,of the latter means is completed and means for subjecting such fluid tothermal influences upon completion of the motorcircuit' to effectdeenergization of said eljectro-magnetically restrained means'subject'to a time element,

4. In a motor controller the'combination with means for establishingstarting and running connections selectively, said means including'electro-rriagnetically restrained -means releasable togefiectestablishment of running connections, and an electro-responsive switchto de-energize said electro-magnetically restrained means, said switchhaving a heating coil dependent for energization upon establishmentofcertain of said first-mentioned connections.

5. In a motor controller the combination The .aforedescribedconstruction and arwith'means for establishing power connecrangementthus provide fonfull automatic control of a transformer starter whilerequiring but seven points at which the power circuit is made or broken,that is to say, one more than twice'the number of lines in the supplycircuit. Moreover, the aforedescribed system of interlocks serves toinsure against operation of said switches except in the manneraforedescribed and also provides against unwarranted re-establishmentjofthe 4 the controller.

closing circuit of any of said switches, while the particular characterof the device 7 provides for accurate electro-thermally responsivetiming of the automatic functions of .What we claim as new and desire tosecure by Letters Patent is: 1. In a motor controller the combinationwith meansfor' establishing different power connections selectively ofmeans for timing establishment of certain of said connections 5 by saidformer means, said latter means including a normally closedelectro-thermal tions for the motor, of electro-thermal meanscontrolling said first-mentioned means and influenced by theestablishment of said power connections to subject saidfirstmentionedmeans to a time element in reestablishing such connections follqwingin-.

terruption thereof under normal conditions. v

6. In a motor controller the combination with means for establishingstarting and running connections selectively, of electrothermal meansresponsive subject to a time element upon establishment'of startingconnections to time the establishment of running connections by saidmeans, said electrothermal means also acting upon establishment ofrunning connections to subject said first-mentioned means to a timeelement in re-establishing the motor connections followin interruptionthereofg In a motor controller the combination with means forestablishing starting and running connections selectively, said. meansincluding electro-responsive switches requiring energization forestablishment of either starting or running connections and Y currentmotor, a

further including electro-magnetically restrained switches requiringenergization to maintain the starting connections and tend ing whende-energized to establish running connections, of electro-thermal meansresponsive to de-energize said electro-magnetically restrained means andto prevent re-energization of said electro-responsive saidelectro-thermal means being responsive subject to a delay uponestablishment of starting connections and being maintained responsivethroughout the@ pemeans,

riod of establishment of running connections.

-8. The combination with an alternating current motor, a plurality oftransformer coils, and a supply circuit, of a controller operable forconnection of said coils to said supply circuit and completion of thecircuit of said motorinclusive ofsaid coils and thereafter operable forconnection of the motor directly to said supply circuit anddisconnection of said coils from said supply circuit andelectro-responsive means' for timing the act-ion of said controller,said means being dependent for energization upon connection of saidcoils to said supply circuit. j

9. The combination with an alternating coils and a supply circuit, of acontroller operable for connection of said coils to said supply circuitand completion of the circuit of said motor inclusive of said coils andthereafter operable for connection of the motor directly to said supplycircuit, and disconnection of said coils from said supply circuit, andan electro-thermally responsive device for timing said latter mentionedoperation of said controller, said the motor to intermediate points ofsaid coils, a second circult controller having jointly movablecontactors to be operated electro-magnetically for connection of saidcoils to said supply circuit and completion of the circuit of said motorinclusive of'said coils and an electro-th-ermally responsive devicearranged to interrupt the energizing circuit of said first-mentionedcircuit controller subject to a time element for permitting saidcircuitcontroller to move into its biased position for connection of theplurality of transformer 1,eeo,405

motor directly to said supply circuit and interruption of theinterconnection of said transformer coils.

11. The combination with an alternating current motor a plurality oftransformer coils and a supply circuit of a circuit controller havingjointly movable contactors biased to a given circuit controllingposition and movable electro-magnetically to a different circuitcontrolling position for interconnection of said coils and connection ofthe motor to intermediate points of said coils, a second circuitcontroller having jointly movable contactors to be operatedelectro-magnetically for connection of said coils to said supply circuitand completion of the circuit of said of said coils and anelectro-thermally reenergizing circuit of said first-mentioned circuitcontroller-subject to a time element for permitting said circuitcontroller to -to closure of other of said switches to thereby interposebetween said motor and a source of supply a plurality of transformercoils, and electro-thermally responsive means associated with saidsource of supply and said electromagnetic means for interrupting theinterconnection of said coils and connection of the motor directly tosaid source of supply subject to a time elemen v 13. In a motorcontroller, the combinat-io with a plurality of switches interposedbetween said motor and a supply circuit, certain of said switches beingnormally open and other of said switches being normally closed,electromagnetic means for substantially simultaneously reversing theposition of all of said switches to interpose a plurality of transformercoils between sai supply circuit and said motor in starting the latter,and electrd-thermally responsive means associated with said supplycircuit and said electro-magnetic means for again reversing the positionof certain of said switches for interruption of the interconnection ofsaid coils and connection of the motor directly to said supply circuit.

14. In a controller for alternating current motors, the combination withan auto-transformer, of means to establish selectively circuitconnections for the motor comprising starting connections involving thetransmotor inclusive 'sponsive device arranged to interrupt the former,and runnin connections, and means controlled by flux o the startinginductance to provide a time element between establish- 'ment ofstarting and running connections of the motor.

15. In a controller for alternating current motors, the combination withan auto-transformer, of means to establish selectively circuitconnections for the motor comprising starting connections involving thetransformer, and running connections, and electro-thcrmally responsivemeans controlled by flux of the starting inductance to provide a timeelement between establishment of starting and running connections of themotor.-

16. In a motor'controller, the combination with eleetro-magneticallyrestrained means for establishing starting connections, and anelectro-thermally responsive switch to release said electro-magneticallyrestrained means for establishment of running connections, said switchhaving a heating coil adapted for inductive energization by the maincurrent upon establishment of certain of said connections.

17. In a controller for electric motors, the combination with means forestablishing selectively starting and running connections for the motor,of electro-thermally acting means to be inductively influenced bycurrent of the motor supply circuit upon completion of startingconnections for timing subsequent establishment of running connections.

In witness whereof, we have hereunto subscribed our names.

THOMAS E. BARNUM.

HENRY N. WADE.

